Cellulose derivative coated fabric



March 10, 1936. D. McBURNEY ET AL 2,033,202

CELLULOSE DERIVATIVE COATED FABRIC Filed July 6, 1933 Dorman m Bur-my INVENTORS A TTORN Patented Mar. 10, 1936 2,033,202 cmunosn DERIVATIVE COATED FABRIC PATENT orrics Dorman McBurney and Edgar H. Nollau, Newburgh, N. Y., assignors to E. I. du Pont de Nemoms & Company, Wllmingto n tation of Delaware 11, Del.-, a cor- Application July 6, 1933,- serlal No- 676,169

2 Claims. (CI. 91-68) This invention relates to cellulose derivative coated fabrics and, more particularly, to such material especially adapted for use in the bookbinding art.

7 Cellulose derivative coated fabrics do not have a satisfactory surface on which to apply ordinary commercial glue or paste, unless the coated surface of the fabric has been specially treated. In the bookbinding art and similar fields where 10 such material is used in large quantities, it is a great disadvantage to work with. material that involves special treatment of the coated surface in order that it may be adhered to some other surface. This is particularly true where it is necessary to adhere the endsheet of a book signature to the turn-ins on the cover of a bookbinding. The present applicants developed a casein composition to be applied to the cellulose ester coated surface of bookbinding material in order to overcome this objection. This composition is disclosed and claimed in United States Patent 1,656,284. While material coated with that composition has had great commercial success, there is an appreciable increase in the cost of manufacturing such material, and there is still room for improvement in reduction of manufacturing costs and also in producing a material better adapted for the wide range of processing which the binder may desire to employ from time to time, without special treatment of the coated surface.

An object of this invention is to provide a cellulose ester coated fabric having the advantageous properties of the material disclosed in U. S.

Patent 1,656,284, but being more economical to manufacture. A further object is to provide a material having a coated surface adapted to be grained and embossed as desired, without injury to the material. A still further object is to provide such a material that may be stamped with goldleaf, re-embossed, or blanked, over a relatively great temperature range. Other objects of the invention will be apparent from the description given hereinafter.

5 The above objects are accomplished according to the present invention by superposing a cellulose derivative film on a fabric backing and applying over said film a solution of gelatin to deposit a thin surface film of. gelatin. More par- 50 ticularly, the invention comprises bookbinding material comprising'a woven or non-woven fabric backing, a cellulose nitrate-softener-pigment film, and a surface film of gelatin, the gelatin 55 ofsurface.

film weighing 0.006-0.06 ounces per square yard In the accompanying drawingthe single figure is a conventional cross sectional view of material embodying the present invention. Reference numeral l indicates a woven fabric bacmng,

2 a cellulose derivative film superposed thereon, 5 and 3 a surface film of gelatin. It will be understood that no efiort is made in the drawing to indicate relative thicknesses with accuracy.

The following example is submitted in order that the method of manufacturing the material 10 according to the present invention may be more clearly understood. The example is merely illustrative:

Example.The customary bookblnding mate? rial is made according to ordinary practice. 1 i. e., a web of suitable fabric is coated on one side with a cellulose nitrate-caster oil-pigment composition such as the following. All parts are given by weight:

- Parts 20 Cellulose nitrate 16 Castor il 26 Dry pigment 10 Benzol 87.8 Alcohol 27,9 25 Ethyl acetate 27.9

As well known in the art, this composition may be applied in several ways, but is preferably applied bymeans of a spreading knife in the usual 30 coating machine. The composition is generally applied in several coats to build up a film of the desired thickness. The preparation of the bookbinding material vup to this point may follow any of the known practices in the art. 5 After the above coating;has been thoroughly, dried, a surface coat of gelatin is then applied over the cellulose nitrate-castor oil-pigment film by means of a doctor knife in a coating machine, or by roller coating, or similar means known in 40 the coating art. The gelatin is applied in the form of an aqueous acetic acid dispersion containing about 3% solids, at the rate of approximately 1 ounce per square yard of surface, depositing a gelatin film weighing about 0.03 ounces per square yard of surface. After the application of this composition the material is passed through a suitable drying chamber as commonly used in the coated fabric manufacturing industry. The

material may then be'embossed in any desired pattern as demanded by the trade. Where the gelatin solution is to be applied on ablack base a small percentage, for example, from0.2-1.0% of an alcoholic nigrosine solution may be added to the gelatin solution in order to improve the color of the finished pmduct.

The gelatin solution is prepared as follows:-

Gelatin is dispersed in hot water and glacial acetic acid to. give a solution as follows (all parts and percentages throughout the specification and claims are given by weight, unless expressly stated otherwise) Per cent Gelatin 12 Water 60 Glacial acetic acid 28 To this solution is added slowly, with agitation to avoid local precipitation, an equal weight of denatured alcohol (U. S. Revenue Formula 23-A comprising 100 parts by volume of 95% ethyl alcohol and 10 parts by volume of C. P. acetone), and finally a solution in an amount equal to double the weight of the solution already prepared is added, having the following composition:

Per cent Denatured alcohol (Formula 23-11) '15 Formaldehyde 25 This gives a'flnal gelatin solution of the following composition:

Proierrod Per cent Per cent Gelatin 3. 0. M Water 15.0 -20 Almhnl 025 110-75 Glacial acetic said.-;-.-.-.; 7. 0 5-10 Formaldehyde l2. 5 1-25 mitted without substantially affecting the properties of the finished Instead of cellulose nitrate, the fabric backing may be coated with a cellulose acetate or cellulose ether composition. A variety of plasticizers, such as dibutyl phthalate, dibutyl tartrate, and other known plasticizers, may be used in place of castor oil. The pigment may be omitted, if desired, but the gelatin solution may be applied equally well to either pigmented or unpigmented cellulose derivativefilms.

A specific practical method of making up a particularly suitable gelatin solution has been disclosed. The alcohol, of course, need not be denatured as the presence of the acetone is not essential. The formaldehyde may be eliminated, although it is preferred to use it, and quite obviously the proportions of the solution may be widely varied as occur to those skilled in the art. Equivalent ac ds, such as tartaric and citricacids, may beTemployed in place of acetic acid, and other alcohols, as methyl, propyl, butyl alcohol, and the like, may be employed in place of ethyl alcohol. The preparation of a suitable gelatin solution is well within the skill of those familiar with the art.

Material prepared according to the present invention is considerably cheaper and easier to manufacture than the material of U. S. Patent 1,656,284. The gelatin solution 'is somewhat cheaper with respect to its ingredients, appreciably easier and quicker-to prepare, and can be stored to much greater advantage than the casein solution of the patent. It is applied directly to pigmented cellulose derivative base coats to much better advantage than the casein composition and does not require an unpigmented top coat of cellulose nitrate composition as sometimes is essential in obtaining a high-grade product where the casein solution is used.

The herein described material has, in general, the same advantageous properties possessed by the casein coated material of U. 8. Patent 1,656,284, but has the very substantial improved property of being able to withstand a much wider range of processing at the bindery without deleterious eflects than the casein coated material. There is no tendency for the gelatin film to flake on embosing the finished material, whereas in the embossing of heretofore known material with certain grains a pronounced and objectionable tendency toward this flaking has been experienced. Not only does the present material allowthe use of a much wider variety of grains in embossing, but the material can be blanked, or re-embossed, or stamped with goldleaf, and the like, over a temperature range of between 200- 400" F., whereas the casein coated material yields best results only when blanked or re-embossed at a temperature of from 200-275 F. This permisslbly wider range is a very material advantage, inasmuch as various binders desire to give bookbinding material a variety of treatments under loosely controlled conditions, and considerable expense and trouble is involved when such treatments are not carried out at suitable temperatures. By radically improving the range of temperature through which the various processes may be carried out, the present invention has provided a material very appreciably improved over the best material for bookbindings, and the like, heretofore known, namely, the casein coated bookbinding material.

As many apparently widely diiferent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

We claim:

1. A non-sticky bookbinding material comprising a fabric base having a coating of a cellulose derivative composition on one side and superposed thereon as a top coat a film consisting of tanned gelatin weighing between .006 and .06 oz. per square yard and containing an acid selected from the group consisting of acetic, citric, and tartaric.

2. A non-sticky book-binding material comprising a fabric base having a coating of cellulose derivative on' one side thereof and superposed thereon as a top coat a film consisting of tanned gelatin weighing between .006 and .06 oz. per square yard and containing acetic acid.

DOB-MAN MoBURNEY. EDGAR H. NOLLAU. 

